Hepatocyte ploidy in cats with and without hepatocellular carcinoma.

BACKGROUND: Domestic cats rarely develop hepatocellular carcinoma. The reason for the low prevalence is unknown. Reductions in hepatocellular ploidy have been associated with hepatic carcinogenesis. Recent work in mice has shown that livers with more polyploid hepatocytes are protected against the development of hepatocellular carcinoma. Hepatocyte ploidy in the domestic cat has not been evaluated. We hypothesized that ploidy would be reduced in peri-tumoral and neoplastic hepatocytes compared to normal feline hepatocytes. Using integrated fluorescence microscopy, we quantified the spectra of ploidy in hepatocellular carcinoma and healthy control tissue from paraffin embedded tissue sections. RESULTS: Feline hepatocytes are predominantly mononuclear and the number of nuclei per hepatocyte did not differ significantly between groups. Normal cats have a greater number of tetraploid hepatocytes than cats with hepatocellular carcinoma. CONCLUSIONS: Total hepatocellular polyploidy in normal cat liver is consistent with values reported in humans, yet cellular ploidy (nuclei per cell) is greater in humans than in cats. Tetraploid cat hepatocytes are predominantly mononuclear.

Pre-operative bevacizumab, capecitabine, oxaliplatin and radiation among patients with locally advanced or low rectal cancer: a phase II trial.

BACKGROUND: To evaluate the safety and efficacy of pre-operative chemoradiation, using capecitabine, oxaliplatin and bevacizumab with standard doses of radiation, in patients with high-risk rectal cancer. METHODS: Patients with locally advanced or low rectal cancer were treated with capecitabine 825 mg/m(2) twice daily on days 1-14 and 22-35, oxaliplatin 50mg/m(2) on days 1, 8, 22 and 29, bevacizumab 5mg/kg on days 14, 1, 15 and 29, and radiation 50.4 Gy in 28 fractions including boost. Total mesorectal excision was performed 7-9 weeks after chemoradiation. The primary end-point was complete tumour regression (ypT0NX) by central review. FINDINGS: Forty-two evaluable patients were enrolled, and 38 proceeded to definitive surgery. Eighteen patients (43%) had clinical T4 tumours and/or N2 tumours. Mean relative dose intensity was >90% for all systemic agents, and 97% for radiation. Grade 3/4 diarrhoea occurred in 10 patients (24%) and pain in 4 patients (10%) pre-operatively, while grade 3/4 pain, fatigue and infection were each reported among 5 patients (13%) post-operatively. Re-operation due to complications occurred in 4 patients (11%). Complete tumour regression (ypT0) was seen in 9 patients (23.7%) of which two had N1 disease and the pathological complete response (pCR) rate (ypT0N0) was 18.4%. Central review changed pathologic stage in six cases (16%). INTERPRETATION: In this study, pre-operative bevacizumab added to oxaliplatin, capecitabine and radiation was safe and resulted in a promising tumour regression rate. Surgical complications were closely monitored and occurred with the expected frequency. Central pathology review should be considered for trials with pathologic response as the primary end-point. FUNDING: British Columbia Cancer Agency, Hoffmann-La Roche Canada and Sanofi-Aventis.